Thumb hole punch



Sept. 6 1955 H. KELLER THUMB HOLE PUNCH 5 SheetsShet l Filed June 2, 1950 Sept. 6 1955 KELLER 2,716,928

THUMB HOLE PUNCH Filed June 2, 1950 3 Sheets-Sheet 2 INVENTOR Ha. wry fie Zler.

Sept. 6 1955 H. KELLER THUMB HOLE PUNCH 5 ShetsSheet 5 Filed June 2, 1950 United States Patent THUMB HOLE PUNCH Harry Keller, Philadelphia, Pa. Application June 2, 1950, Serial No. 165,742

2 Claims. (Cl. 93-585) The present invention relates to thumb hole punches of the character which will cut thumb hole recesses simultaneously in the opposite walls of boxes, cartons and the like.

A purpose of the invention is to accomplish the punching of thumb holes by electric solenoid actuation of opposed punches.

A further purpose is to make the solenoids and associated mechanism readily adjustable toward and away from one another.

A further purpose is to trigger the solenoid action by a switch closed by motion of a floating work table on which the work is placed, preferably pivoting the work table and spring urging it upwardly.

A further purpose is to provide recesses in the work table through which the solenoids can move in adjustment. Iii

A further purpose is to laterally slot the dies cooperating with the punches and to extend the slots to a position in line with the depressed position of the work table.

Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate one only of the numerous embodiments in which my invention may appear, selecting the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

Figure 1 is a perspective of the device of the invention.

Figure 2 is a top plan view partially in axial section through one of the punches.

Figure 2 shows the punches in close adjustment, whereas Figure 1 shows the punches in wide adjustment.

Figure 3 is an elevation of the punch of the invention, partially in axial section.

Figure 4 is a section on the line 44 of Figure 2.

Figure 5 is a fragmentary section on the line 55 of Figure 4.

Figure 6 is a fragmentary diagrammatic perspective of the solenoid armature and punch of one of the solenoids, armatures and punches.

Figure 7 is a bottom perspective of the work after completion of the punching operation.

Describing in illustration but not in limitation and referring to the drawings:

In the prior art it has frequently been desirable to punch finger holes or thumb holes on the bottom edge of the top portions of boxes and cartons. The mechanism for doing this has frequently been complicated and subject to high maintenance.

In accordance with the present invention, the punches are operated electrically by solenoids, and placed in opposed position which is made adjustable to any size of box.

The solenoids are actuated by slight downward pressure on the work table at a time when the work is positioned in side slots of the dies, thus assuring against premature or unexpected punch action. The Work table is suitably provided with opposed recesses through which the adjustment of the solenoids takes place.

' 55 acting against a plunger 56 T the box is aligned by the guide The work table is desirably upwardly urged and pivots, closing a spring under downward pressure.

The thumb hole punch of the invention comprises a base supporting adjustment bearings 21 from a plate 22 secured across a longitudinal recess 23 in the base. The bearings rotatably mount a screw 24 having at opposite ends right and left hand threads 25 and 26 respectively. The screw is turned by a grip 27.

Yoke nuts 28 carry internal threads cooperating with the respective threads on the screw, and suitably interconnect with and mount solenoid brackets 30 which ride back and forth with the nuts on the top guiding portion 31 of the base.

Each of the solenoids is suitably identical, and comprises a solenoid core 32 supported on studs 33 from the bracket 30, and carrying a solenoid winding 34. A solenoid armature 35 extends through the usual recess in the core at the axis of the coil, and carries on its forward end a punch 36 suitably having an arcuate forward punch surface 37 as shown in Figure 3.

The punch extends through and cooperates with a female punch die 38 mounted in an opening in the bracket 30 and having a side work receiving slot 40 which is desir ably upwardlydirected in the case of both punches. The slot extends to a level which corresponds with the depressed level of the work table later to be described.

The solenoid is conveniently surrounded by a tubular casing 41 closed by and end closure 42 secured in place by bolts 43 threading into the bracket 30. A spring abutment 44 extends outwardly at one side of the punch at the point of interconnection between the armature and the punch, and is engaged by retracting tension springs 45 anchored at 46 in the core structure.

The solenoids extend in opposed relation with the punches and dies directed toward one another, and move in recesses 47 of a suitably generally horizontal work table 48. The recesses extend to approximately the center of the table, at which they are separated by a web 50 depressed at 51 to permit the dies to extend above the web in the close adjusted position of Figures 2 and 3.

The table is pivoted at 52 on a bracket 53 extending out from the base, preferably to a position remote from the line between the punches. The table when in inactive position is upwardly urged by a spring 54 in a spring well which is adjustably connected to the table at 57 so as to permit adjustment of the raised position. The position of the screw adjustment can be changed by turning finger hold 58.

Suitably adjoining the spring 54 is a switch operator 60 extending downwardly from the bottom of the table and adjustable as to height by a screw 61 manipulated by a grip 62. The switch operator engages an electric switch 63 when downward pressure is applied to the table, closing the electric circuit from a source of alternating or direct electric current in the circuit through cord 64, to the individual solenoids, which are desirably connected in parallel on the load side of the switch 63.

The work table is provided with a series of recesses 65 for receiving screw 66 which mounts guide 67 for positioning the rearward edge of the box 68. In operation it will be evident that the box 68 is placed on the work table in inverted position as shown by the dot-and-dash lines in Figure 3, bringing the opposite sides or ends of the box into the slots of the dies. The rearward edge of 67. Slight downward pressure by the box against the work table when in this position will rock work table about its pivot 52, compressing spring 54 and causing the Work table to move down sufliciently to close switch 63, which electrically connects the solenoids to the source in order to energize the solenoids. The solenoids upon energization pull their armatures toward one another, moving the punches t0- 3 ward 'one another in the dies, to cut out the thumb holes 70 in the lower edges of the sides or ends of the box or other work. As soon as the. work is lifted the pressure on the work table is relieved and the work table rises can also be adjusted as required-to suit the size of the work.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in'the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a thumb hole punch, a work table having opposed recesses, a pivotal mounting for the work table at one side of the recesses, spring means urging the work table into limiting upper position, an electric switch positioned'beneath the work table to be closed thereby, opposed solenoids mounted in line with the work table re cesses and operatively electrically connected to the electric switch, means for adjusting the solenoids toward and away from one another while moving the solenoids in the recesses of the work table, the solenoids having armatures, punches in line with the solenoids and supported on the armatures and upwardly slotted dies cooperating with the punchesQthe slots of the dies extending to a position on a level with the depressed position of the work table.

2. A thumb hole punch comprising a support, a screw oppositely threaded on its two ends and mounted on'the support to rotate on a lateral axis of that support, a bracket mounted centrally on the support and extending at once rearwardly and upwardly therefrom, a work table roughly in the shape of an H with broad main legs with the upper surfaces of the two main legs forming one plane and part of the cross arm depressed therebelow, said work table being mounted on the rear upward end of the bracket to pivot about an axis approximately parallel to the screw and along one of the main legs of the H, with the rest of the H extending toward the front and the depressed portion of the cross arm located over the screw, opposed solenoid armatures mounted on opposite ends of the screw to travel in opposite directions on the turning thereof and located between different halves of the legs of the H, solenoids in the armatures mounted to jumpxtoward each other under the influence of current, punches on the solenoids, walls associated with the armatures and forming holes for the punches in said direction of travel and forming also slots in from the top perpendicular to the travel of the punches at a point along the path of said travel before the ends of the holes are reached, spring means for retraction of the punches, said work table having an upper and a lower position representing a slight difference in angular positioning about the pivot on the bracket but-in eachof whichthe plane of the top surface of the legs of the H is at least close to horizontal andthe lower position having the plane in registry with a predetermined level onthe holes, a spring onthe bracket urging the work table to open position, and a switch, biased to open position, mounted on the-bracket and forming part of the solenoid circuit which switch is depressed into closed position by the work table when it goes into its lower posit-ion and is in open position when the work table is in its upper position.

References Cited in the file of this patent UNITED STATES PATENTS 1,092,393 Reifsnyder Apr. 7, 1914 1,117,321 Carlson Nov. 1 7, 1914 1,287,137 Thomas Dec. 10, 1918 1,367,513 Mann Feb. 1, 1921 1,684,296 Brodsky Sept. 11, 1928 1,834,201 Brodsky Dec. 1, 1931 2,155,578 Anderson Apr. 25, 1939 2,329,020 Wales Sept. 7, 1943 2,501,685 Lev Mar. 28, 1950 1 FOREIGN PATENTS 409,749 Germany Feb. 10, 1925 

